OSM-4OC12-POS-X and BGP

[switchtower]

Hello,

I'm having a hard time trying to determine whether this line card with 512MB of ram will be able to hold the full BGP table from 3 different providers (2 ATT, MCI, and Savvis). The company I work for will be replacing two older 12000 series routers because the current line cards in them are being exhausted by CEF.

The plan was to purchase a 6509 with a Sup 7203BXL and this line card. The reason for a 6509 an not a 7600 is our infrastructure is standardized on these devices.

If any other information is needed, please let me know!

--Nick

[mchin345]

When running full Internet BGP routes, I recommend at least 128 MB of RAM on the line card. The recommendation to alleviate this problem would be to increase the memory on the GRP (say to 512MB).This should help accommodate the increases CEF & routing table sizes.

For further information about line card click this link.

http://www.cisco.com/en/US/prod/collateral/modules/ps2831/ps4373/product_data_sheet09186a008009223e_ps368_Products_Data_Sheet.html

[switchtower]

The maximum amount of memory that is supported on the line card is 512MB. If there are 4 OC-12 connections, that only allows for the minimum amount of memory per connection.

Will 128MB be sufficient for future growth, or should I separate the 4 OC-12 line cards into two 2 port line cards?

Thanks

[Giuseppe Larosa]

Hello Nick,

the CEF table doesn't increase with the number of ports in the linecard: it is built from topology as it is known by the router as a whole.

So the size of memory depends from how many routes are in your router : if it has multiple eBGP sessions with ISP importing multiple BGP full tables or only one thousand routes and a default route this makes the difference.

Be aware that if a linecard cannot host the whole CEF table in a GSR CEF is disabledthe linecard and its ports cannot forward anymore (no other switching options here).

Hope to help

Giuseppe